Herbs & Botanicals
Flaxseed (ya ma zi)
What is flaxseed? What is it used for?
Flax is an annual herb which is believed to have originated in Egypt, but is now grown worldwide. Flax is one of the oldest cultivated plants in history; passages in the Bible mention that Jewish high priests wore garments made from flax, and flax-woven cloths and flaxseeds have been found in Egyptian tombs.
Flaxseed has been used therapeutically for thousands of years. As far back as the first century, Pliny the Elder listed more than two dozen remedies that included flaxseed, for conditions ranging from constipation to inflammation. It is still listed in the official Chinese pharmacopeia as a treatment for constipation and dry skin. In Europe, it is used as a laxative and to reduce skin inflammation. The German Commission E has approved the use of flaxseed (internally) for chronic constipation, gastritis, enteritis, and to treat colons damaged by overuse of laxatives.
The main ingredient in flaxseed is an oil, which contains several essential fatty acids, including linoleic and alpha-linolenic acid. Research has shown that flaxseed oil may help lower cholesterol and blood pressure levels, and in some cases, may be a possible replacement to fish oil for people who are allergic to fish. Its main use, however, as previously mentioned, is to treat constipation.
How much flaxseed should I take?
Although it cannot be used in cooking, some people use small amounts of flaxseed oil (1 tablespoon or less), and occasionally whole flaxseeds, on salads or vegetables to add flavor and for dietary purposes.
What forms of flaxseed are available?
Flaxseeds are available whole and dried, or ground as a powder for use in decoctions and poultices. Extracts and tinctures made from flaxseed oil are also available.
What can happen if I take too much flaxseed? Are there any interactions I should be aware of? What precautions should I take?
Flaxseed and flaxseed oil are safe when taken as directed, especially when taken in a 1:10 flaxseed/liquid ratio. When taken under such precautions, no known side-effects have been reported. While there are no drug interactions with flaxseed, its absorptive properties may prevent some drugs from being absorbed into the body properly. As always, make sure to consult with a licensed health care provider before taking flaxseed, flaxseed oil, or any other herbal remedy or dietary supplement.
- Allman MA, Pena MM, Pang D. Supplementation with flaxseed oil versus sunflower seed oil in healthy young men consuming a low-fat diet: effects on platelet composition and function. Eur J Clin Nutr 1995;49(3):169-178.
- Blumenthal M, Goldberg A, Brinckmann J (eds.) Herbal Medicine. Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications, 2000, pp. 134-138.
- Bown D. Encyclopedia of Herbs and Their Uses. New York: DK Publishing, Inc., 1995, p. 304.
- Shields PG, Xu GX, Blot WJ, et al. Mutagens from heated Chinese and U.S. cooking oils. J Natl Cancer Inst 1995;87:836-41.
- Thompson LU, Rickard SE, Orcheson LJ, et al. Flaxseed and its lignan and oil components reduce mammary tumor growth at a late stage of carcinogenesis. Carcinogenesis 1996;17:1373-6.